[MISSHA] (U-OUTLET) MASCURE WHITENING SOLUTION SHEET MASK. This is a sheet mask that contains glutathione and niacinamide as the main ingredients to brighten the skin and reduce dark spots. It also has a skin-friendly formula that is mild and safe for sensitive skin. How to use: 1. After facial cleansing, adjust skin texture with toner. Place the sheet on your face. 2. After 15 - 20 minutes, remove the sheet and dab the remaining essence on the face for absorption.